Loom with traveling shed

ABSTRACT

A flat or circular loom produces a flat or tubular fabric in a multiplicity of web sections each served by an individual weaving unit including a weft needle whose thread, after traversing the shedded warp threads of the associated section, is engaged by the weft thread of an adjoining needle whereby an interlinked chain of weft loops is formed to act as a filling. An intermittently operable thread clamp prevents a contraction of a loop prior to its engagement by the next weft needle and, especially in a flat loom, may also be used to draw the node between two loops into the fabric of the preceding section. In a circular loom, a loop inverter associated and synchronized with each weft needle causes the cross-links between the nodes of adjacent tiers to come to lie on the inside of the tubular fabric.

I Umted States Patent [151 3,664,380

Haberhauer et al. 51 May 23, 1972 [54] LOOM WITH TRAVELING SHED OTHER PUBLICATIONS [72] Inventors; Karl Babel-ban"; Hertha Haberhauer 1,072,569 German Publication to Haberhauer of Dec. 1959.

both of Grunstadt, Germany P Ex H S. J d [73] Assignee: Weinheimer Gummiwerke Gesellschaft nmary ammer enry au on Attorney-Karl F. Ross mlt beschrankter Haftung, Mannheim. Germany 57 ABSTRACT [22] Filed: May 8, 1970 A flat or circular loom produces a flat or tubular fabric in a PP N04 35,818 multiplicity of web sections each served by an individual R l ted us. A n ti weaving unit including a weft needle whose thread, after 8 8 pp ca on Data traversing the shedded warp threads of the associated section, Continuation-impart of ly is engaged by the weft thread of an adjoining needle whereby 1969. an interlinked chain of weft loops is formed to act as a filling. [30] Foreign Application Priority Data An intermittentl operable thread clamp revents a contracy P tion of a loop prior to its engagement by the next weft needle J l 5, 1969 i u y Germany P 19 34 298 4 and, especially in a flat loom, may also be used to draw the 52 U.S. c1 ..139/12, 139/13 139/116 mde between fabric Preceding 39/124 tion. In a circular loom, a loop inverter associated and 51 1m. (:1 ..D03d 47/06, D03d 47/26 Synchronized with each needle causes the [58] Field of Search ..139/11, l2, 13, 116, 122, 124 R, between the nodes of adjacent tiers to come to lie on the in- 139/124 A side of the tubular fabric.

[56] References Cited 15 Claims, 23 Drawing Figures UNITED STATES PATENTS 3,556,165 l/1971 Zmatlik ..139/124 R PATENTEDMAY 23 I912 I a. 664. 380

SHEET 1 [IF 9 Fig. 23

H11 ll KARL HABERHAUER HERTHA HABERHAUER INVENT0R.

57 y SS Attbrney PAIENTEDMAY 23 I972 3, 664. 3 8O sum 5 or 9 Fig. 9

Karl Haberhauer Herfha Haberhauer INVENTORS.

I Attgrney PATENTEDMAY 23 I972 R 664, 380

sum 5 OF 9 mmvroas KARL HABERHAUER HERTHA HABERHAUER R s; r Attorney PATENTEUMAY23 I972 8. 664, 380

sum 7 BF 9 FIG. /4 FIG. /5

. I93 Karl Haberhauer I97 Hertha Haperhauer INVENTORS. F IG. 7

Attorney LOOM WITH TRAVELING SHED This application is a continuation-in-part of our copending application, Ser. No. 849,564 filed July 23, 1969.

Our present invention relates to a loom with traveling shed.

Such a traveling shed, i.e. a progressive separation of a set of parallel warp threads into an upper and a lower warp in step with the advance of a weft carrier across the array, is designed to facilitate the weaving of relatively wide webs in which it is difficult to drive a shuttle across the fabric with the aid of a picker stick. The shuttle, in a conventional loom of this type, is cammed forward by successive reeds moving along the warp threads in phased relationship with the opening and closure of the shed. This method is not free from drawbacks, including the risk of dislocation of the slender reeds and the sharpening of their edges involving potential damage to the cloth.

The general object of our present invention is to provide an improved loom of the traveling-shed type which obviates these disadvantages.

A more specific object is to make such a system available to the weaving of tubular fabrics.

In aloom embodying our invention, a multiplicity of substantially identical weft carriers are disposed in a row across the array of warp threads,'each weft carrier having a limited sweep over only a part of the width of the array. The sweeps of adjoining weft carriers intersect and are so timed that the weft of any carrier except the last one is interlinked with the weft of the next-following carrier to form therewith a continuous chain traversing the warp. The staggered operation of the weft carriers is synchronized with the progressive shedding so that each carrier inserts its weft into a shed just formed in the corresponding web section, the shed being closed promptly upon the withdrawal of the carrier whereupon the inserted weft is beaten against the fell of the cloth by a lay or batten individually assigned to that section. At the opposite edge of the fabric, the last weft may be engaged by a selvedge needle or equivalent implement, with or without interlinking with the thrums of previously inserted fillings, until the weft chain has been locked up in the fabric structure.

The weft carrier most suitable for use in our improved loom is a preferably curved needle swingable about a pivot which may substantially coincide with its center of curvature. As this needle reciprocates through the shed, it forms a generally triangular loop of the entrained, doubled weft thread, with the vertex of the triangle projecting beyond the shed. The use of warp dividers mounted ahead of the batten, or directly carried thereon, insures a sufficient separation between adjoining groups of warp threads to make the vertex of the triangle accessible to the tip of the next needle carrying its own weft thread through the loop and thence across the adjacent shed. As the first needle withdraws, the second needle again forms a triangle for engagement by the tip of the third needle, and so When the second needle has detached itself from the chain of loops so formed, the first needle in the final phase of its withdrawal stroke applied additional tension to the chain and, if its thread supply is blocked at that instant by the closure ofa thread clamp, tends to draw the node between this loop and the next one into its own shed so that this node is offset from the boundary between the corresponding fabric section and the section served by the second weft needle. The extent of this offset can be varied by differently timing the clampdown of the weft supply during successive loom cycles whereby the nodes are more or less randomly distributed across the fabric and partly hidden by the overlying warp. Since the nodes of adjacent weft chains are cross-linked by short lengths of weft thread at the roots of the loops, the disalignment of the nodes prevents these cross-links from forming continuous lines parallel to the warp superimposed upon the desired fabric pattern.

In order to facilitate the interlinking of consecutive loops within a chain, the pivotal axes of the weft needles are advantageously tilted at a small angle to a line perpendicular to the web plane whereby the sweep of the needle tip arches out of that plane over an arc spanning the corresponding web sectron.

The weft thread entrained by each needle may pass through a tubular part of the needle itself or may be engaged by an eye at the tip thereof. In either case, this weft thread may be stretched during the final phase of the insertion stroke by the operation of the aforementioned thread clamp to preserve the triangular loop to be engaged by the next needle. The fulcrum of each needle may be located at or near a median line of its assigned web section.

The same principles can be utilized for the weaving of a tubular fabric web on a circular loom. In a preferred construc tion of this type, the needles have a radius of curvature greater than that of the fabric tube so that they may operate along the outer periphery of that tube. In such a case, of course, no edging is necessary since the several weft needles interlink their entrained loops in cyclic succession.

According to an advantageous feature of a circular loom embodying our invention, each weft needle is associated with a loop inverter which causes the cross-links between adjoining weft chains to come to lie on the inside rather than on the outside of the fabric. Thus, the tubular fabric need not be turned inside out after the weaving process to hide the seams or welts resulting from the cross-linked nodes, even if they are not randomly staggered or withdrawn into the preceding shed as described above.

In both types of loom, i.e. the flat and the circular one, the successively operating battens may be provided with reed-carrying extensions interleaved with the reeds of the preceding battens over part of the width of a web section, preferably half that width. Thus, the reeds of each batten may have twice the usual spacing, i.e. double the spacing of the warp threads, so that the interleaved reeds of adjoining battens have the proper mutual separation. In a flat loom, of course, the nonoverlapping portions of the first and the last batten should have the usual reed spacing corresponding to the separation of the warp threads. The effect of this overlap is to obliterate the boundaries between adjoining web sections so as to produce a continuous fabric notwithstanding the original separation of these sections by the aforementioned warp dividers.

Alternatively, in a loom of the circular type, the reeds may project radially from a wobbling ring engaged by a swash plate whereby the reeds are continuously moved toward and away from the fell of the tubular cloth in a progressive wave motion.

The invention will be described in greater detail with reference to the accompanying drawing in which:

FIG. 1 is a somewhat diagrammatic view, in sectional elevation, of the principal elements of a fiat loom embodying our invention;

FIG. 2 is a diagrammatic top view of several juxtaposed weaving units of the same loom;

FIG. 3 is a top view of the part of a fabric made by the loom of FIGS. 1 and 2;

FIG. 4 is a view similar to FIG. 1, illustrating a modified loom construction;

FIG. 5 is a fragmentary front-elevational view of a reed assembly forming part of the loom shown in FIG. 4;

FIG. 6 is a plan view ofthe assembly shown in FIG. 5.

FIG. 7 is an enlarged diagrammatic top view of some of the weaving units of FIG. 2, in an alternate position;

FIG. 8 is a view generally similar to FIG. 3, showing a modified fabric structure;

FIG. 9 is a view similar to FIGS. 1 and 4, illustrating a further embodiment;

FIG. 10 is an elevational detail view illustrating a partial modification of the system of FIG. 9;

FIG. 11 shows, in sectional elevation, a circular loom according to our invention;

FIGS. 12 and 13 are detail views illustrating successive stages in the formation of a node by the loom of FIG. 11;

FIG. 14 is a diagrammatic plan view showing two pairs of interlinked weft loops;

FIGS. 15 and 16 are views similar to FIG. 14 showing successive steps in the inversion of a loop node by the mechanism of FIGS. 12 and 13;

FIG. 17 shows a rocker arm forming part of the loom of FIG. 11;

FIGS. 18 and 19 are isometric views illustrating the coaction of two weft needles in the system of FIG. 11 in successive stages of operation;

FIG. 20 is a more comprehensive view of the weaving mechanism of FIG. 11, showing several rocker arms of the type illustrated in FIG. 17;

FIG. 21 shows, in sectional elevation, a harness mounting for controlling the warp in the loom of FIG. 11;

FIG. 22 is a fragmentary cross-sectional view taken on the line XXII XXII of FIG. 11; and

FIG. 23 is a view similar to FIG. 3.

In FIGS. 1 and 2 we have shown the main components of a flat loom embodying our invention, including a warp beam 1 from which a set of warp threads 2 are guided past a tensioning device 3 and a set of tension-monitoring thread guards 4 through heddles 5 of two groups of harnesses designated 5a, 5b, 5c, 5d, 5e, 5f, and 5a, 5b, 5c, 5d, 5e, 5}"; the warp threads then continue between the reeds of a group of lays or battens 6a, 6b, 6c, 6d, 62, 6f, 6g 6n (generally designated 6 in FIG. 1) to the fell 7 of the cloth 8 which passes around transport rollers 10, 9, 1 1 to a takeup roll 49 (see FIG. 4).

A housing 12 rigid with the loom frame, not further illustrated, supports a set of weft needles 15a 15n (generally designated 15 in FIG. 1) which are carried by arms 14 on respective shafts l3 journaled in the housing; the shafts 13, and therefore the pivotal axes of the needles 15, are parallel to one another and inclined at a small angle to the vertical, thus to a line perpendicular to the generally horizontally moving warp. A lever 16 rigid with shaft 13 is articulated to a pitman 17 which in turn is linked with a bifurcate lever 19 fulcrumed at 18. A cam 21 on a shaft 20 is straddled by the prongs of lever 19 and controls the swing the of needle 15 about its pivotal axis. The several cams 21 are relatively offset on shaft 20, which is continuously driven in step with a similar cam shaft (not shown) controlling the rise and fall of the harnesses, so as to swing the corresponding needles 15a 15n in mutually staggered relationship; the swing angle of each needle, as more fully shown in FIG. 7 described hereinafter, is assumed to be greater than 90.

Each weaving unit of the loom, including one of the needles 15a 15n and the associated lay 6a 6n as well as a pair of harnesses such as 5a and 5a, serves a group of warp threads 2a 2n designed to form respective sections of the web 8. In the embodiment under discussion, the cams 21 as well as the harness cams are progressively dephased by 60 so that the traveling shed formed by the harnesses advances across the warp at a rate of six weaving units per cycle (i.e. per revolution of shaft 20). Thus, needles 15a, 15g and every 6th needle thereafter operate in the same phase, as do the associated battens 6a, 6g, etc. and the corresponding heddles which therefore are shown mounted on a common harness such as 5a and 50'. It should be understood, however, that the weaving pattern need not repeat identically after every six web sections and that, therefore, the ganged heddles of any harness need not engage the warp threads of different sections in the same sequence.

For reasons which will more clearly appear hereinafter, the needles 15 are curved approximately along a circular arc centered on their pivotal axes and are hollow so that weft threads 22 (cf. FIG. 4) can be supplied from reels 22 to their tips through the needle body. In the position illustrated in FIG. 2, needle 15a (and correspondingly needle 15g) has just completed its insertion stroke across the warp of web section 20 so that its tip projects from the shed, needle 1512 having swung toward the point of emergence of needle 15a to enter between that needle and its thread 22a as the latter begins to withdraw (cf. needle 15f). The advancing needle 15b entrains its own thread 22b through the loop formed by the thread 22a and carries it through the shed of section 2b for subsequent linkup with the thread 22c of needle 150. The movement of the battens 6a 6f is so synchronized with the swing of needles 15a 15f that the reeds of each batten strike the fell 7 (as shown for batten l6) shortly after withdrawal of the corresponding needle (e. g. 15d) behind the fell line. As the batten recedes from that line, the needle reverses its swing (as shown for needle l5e) preparatorily to entering the opening shed of its section (2e). The cycle is then repeated. Also shown in FIG. 2 is a selvedge needle 50 mounted via an arm 51 on an oscillating shaft 52 which is synchronized with shaft 20 and other cam shafts of the system to engage the loop formed by the final weft thread 22n upon the emergence of the last needle 15n from the fabric edge 53. AFter the batten 6n has performed its beating operation, selvedge needle 50 is withdrawn preparatorily to its engagement with another such loop at the end of the next cycle.

FIG. 3 shows in greater detail a part of the fabric 8 in which successive weft chains, formed by interlinked loops of threads 22a, 22b, 22c, etc., are interwoven with the several groups of warp threads 2a -2f. It will be noted that the junctions or nodes of these loops come to lie along the boundaries between the web sections defined by these groups of warp threads, thus forming welts or seams W which in many instances will not be objectionable. As described hereinafter with reference to FIGS. 7 and 8, however, these nodes can be offset from their section boundaries by temporarily stopping the release of fresh thread to the withdrawing weft needles.

A clamping mechanism enabling such temporary thread stoppage, under the control of a programmer not shown, has been illustrated in FIG. 4 where the housing 12 carries a bracket 23 supporting the reel 22. The thread 22 payed out from this reel, after passing a conventional thread brake 24, is engaged by a clamp having two relatively movable jaws 25, 25. Jaw 25 is stationary whereas jaw 25', urged toward jaw 25 by a spring not shown, is normally held our of contact therewith by a cam (also not shown) on shaft 20 bearing upon a pin 27 rigid with jaw 25'. An upper and a lower eyelet 26, 26 guide the thread 22 past the clamp 25, 25. The cams driving the several pins 27 are, of course, staggered on shaft 20 in the same manner as the needle-controlling cams 21.

FIG. 4 also illustrates the means (not shown in FIG. 1) for operating the battens in synchronism with the weft needles and the harnesses. For this purpose, each batten 6 is rigid with a two-arm lever 32, pivoted to the housing 12 at 31, which is articulated to a cam follower 33 co-operating with a further cam (not shown) on shaft 20. In this embodiment we have also indicated a second set of battens, generally designated 6, whose reeds project between the warp threads from below in interleaved relationship with the downwardly extending reeds of the battens 6 as more fully described hereinafter with reference to FIGS. 5 and 6. Each batten 6' is driven by a linkage 32, 33, fulcrumed at 31', from a cam 34 on a shaft 20 synchronized with shaft 20. Upper and lower rods 42, 42' limit the rise and fall of the warp threads to prevent their disengagement from the reeds of the battens 6, 6'. A ledge 36 supports the cloth 8 at its fell 7.

FIGS. 4 and 5 show some of the upper battens 6a, 6b, 6c together with corresponding lower battens 6b, 60'. It will be noted that each of these battens carries a number of reeds whose spacing is twice that of the warp threads 2 but that the reeds of the upper and lower battens are interleaved so that any warp thread is bracketed, as in a conventional loom, by a pair of reeds. It will further be seen that corresponding battens, such as those shown at 6b, 6b, are relatively ofiset by half the length of a batten in the direction of the fabric width, the length of each batten equaling the width of a warp section 2a, 2b, etc. Owing to this staggered arrangement, a group of warp threads such as 2b will be beaten against the fell 7 of cloth 8 by the simultaneously reciprocating upper and lower battens (such as 6b, 6b) with the aid of reeds which have the normal separation over half the width of the section (here at left) and double that separation over the other (right) half, the latter half being further beaten up during the subsequent phase of a cycle by the batten 60' which overlaps the batten 6b with interleaved relationship of their respective reeds. The bridging of adjoining sections by the lower battens, therefore, obliterates the boundaries between the sections which are separated by warp dividers 35.

In FIG. 7 we have shown the needles c 15g, together with their pivotal axes 13c 13g and supporting arms 14c 14g (illustrated only schematically), in a position preceding that of FIG. 2. Whereas in the latter Figure the needle 15g is on its withdrawal stroke and the needle 15c has just reversed itself to start on another insertion stroke, we have represented in FIG. 7 a situation in which needle 150 is in the terminal phase of withdrawal, with batten 6b (not shown in FIG. 7) about to strike the fell 7, while needle 15g has come to rest in the shed of warp section 2g. Needle 15e has just cleared its shed whereas needles 15d and 15f occupy positions intermediate those of needles 15c, 15c and 15e, 15g, respectively.

Since the triangular loop defined by the thread 223 must not be substantially deformed by the tension exerted upon thread 22f by the withdrawing needle 15f, thread 22g should be clamped upon or just prior to completion of the insertion stroke of needle 15g, the same being true of all the other needles with the possible exception of the first needle 15a (FIG. 2). As each needle 15c 15f withdraws, the node formed between its own thread and that of the needle next in line is localized in the vicinity of the boundary between two warp sections where the first-mentioned thread emerges from the fabric 8 at fell 7. This is best illustrated in FIG. 7 for the node N formed between threads 22c and 22d in the space between the last warp thread of section 20 and the first warp thread 2d of section 2d. If, however, thread 15c is clamped at this instant along with thread 221; whose needle 15b (FIG. 2) is now approximately stationary at dead center, node N, is drawn into the shed of section 20 as illustrated for the node N,, and warp section 2,,. The extent of this node shifting depends, of course, on the timing of the closure of clamp 25, (FIG. 4) about the thread 22c. With threads 22d, 22c and 22f unclamped at that moment, the shifting of node N, has no effect upon the position of subsequent nodes. With the reversal of the sheds after the beating operation, the nodes N N are locked in by the warp threads of sections 212, 2c while weft threads 22c, 22d emerge from the fabric between warp threads 2b, 2c and 2c 2d, respectively.

Selective clamping of the weft threads at pseudo-random intervals, determined by the aforementioned programmer, thus shifts the nodes N N, N of adjacent fillings to the left of the shed boundary 2" FIG. 8, to different positions within the fabric so that the welts W shown in FIG. 3 are broken up and disappear in the pattern; the cross-links L, L, L" between nodes of adjoining tiers are no longer parallel to the warp and become an integral part of the weave.

The loom construction of FIG. 9 differs from that of FIG. 4 in that the two sets of battens 6, 6 are mounted on levers 37, 37 below the warp, both sets of levers being swingable on a common pivot shaft 31' under the control of cam followers 38 articulated to levers 37 and similar cam followers, not shown, linked to levers 37'. These cam followers co-operate with respective sets of cams, such as 39, on a common shaft 40 within a housing 12'. This housing also contains the aforedescribed mechanism for oscillating the needles 15, including shafts 13' controlled by cams 21' on shaft 40. The thread clamp 25, 25 27 of FIG. 4 is now mounted on housing 12' below the warp support 36, the weft 22 passing from its supply reel 22 via thread brake 24 through a tubular standard 43 to the lower part of the loom frame. The standards 43 of the several weaving units may take the place of the warp dividers 35 shown in FIGS. 6 and 7.

In the modified arrangement of FIG. 10, the levers 37, 37' have been replaced by a pair of levers 41, 41, lever 41 passing between the warp threads 2 to act as a warp divider. As in the system of FIG. 4, these two levers carry respective battens 6, 6 whose reeds enter between the warp threads from above and from below, respectively.

We shall now describe, with reference to FIGS. 11 22, a circular loom embodying the principles of our invention.

This machine comprises a frame 101 on which a tubular post 102 is rigidly mounted. Post 102 carries a stationary head 103 overhanging a tube 115 also rigid with it. A camming sleeve 116 inside tube has a groove 116' (FIG. 22) engaged by lugs 118 at the lower ends of a set of loop inverters 104 whose operation will be described in detail hereinafter with reference to FIGS. 12 and 13; see also FIG. 20. Thestems of inverters 104 are lodged in vertical flutes 102 of post 102. Sleeve 116 is fixedly secured to tube 115, the latter in turn being surrounded by a collar 123 which forms a downward extension of head 103.

Members 103, 123 are traversed by a set of vertical shafts 125 (only two shown in FIG. 11, 20 and 21) which surround the post 102 in a peripheral array of as many such shafts as there are weaving units to operate on respective sections of a tubular fabric 142 centered on the axis of post 102. The number and peripheral spacing of the loop inverters 104 corresponds to that of the shafts 125. These shafts carry, above the head 103, respective weft needles 127 generally similar to the needles 15 of the preceding embodiment. The lower end of each shaft 125 is keyed to a pinion 124 in mesh with a gear 121 whose shaft 122 depends from a bottom flange of collar 123. An eccentric pin 120 on gear 121 engages in a camming groove 119 on the face of a spur gear 114 journaled on post 102, gear 114 being driven via an intermediate gear 113 from a gear 112 on a main drive shaft 111 paralleling the post 102. Shaft 11 is rotated by way of a belt 170 and a sheave 171 from a motor not shown and is also provided with a handwheel 153 for manual rotation. The shaft of gear 113 is supported by a beam 101 forming part of frame 101, another such beam 101" supporting the shaft of a similar gear 130 driven by a gear 131 on shaft 111. Gears 131, 130 drive a gear 129 journaled on head 103 at a speed determined by the tooth ratio of these gears; this speed can therefore be varied by substituting another gear 132 for the drive gear 131 and relocating the gear 130 on its support 101" to complete the power train. Similar adjustments, of course, may be made in regard to the speed of drivengear 114.

A platform 133, resting on head 103, supports a multiplicity of upper harnesses 144 and lower harnesses 144 of which only two diametrically opposite pairs have been illustrated in the drawing. These harnesses have the shape of slightly inclined tubes traversed by respective warp threads 137, 137" drawn from nonillustrated supply bobbins and wound several times around transport rollers 136 which are interconnected by a bevel-gear transmission, not shown, and are driven by a worm on shaft 111 engaging a worm gear 107 coupled with that transmission. The harnesses 144, 144' are articulated to platform 133 by means of respective parallelogrammatic linkages 106, 106 with radially spaced pivots 143 as best seen in FIG. 17; the warp threads 137, 137' are led around rollers 138, 139 and past thread guards 140 as well as thread guides 141 to the outer ends of the harness tubes from whose inner ends they descend nearly vertically toward the fell 142 of the tubular fabric 142 (FIG. 20). Some of the lower harnesses 144 are provided with extensions 145' acting as warp dividers to facilitate the entry of weft needles 127 into the shed defined by a group of relatively offset upper and lower. harnesses; the swing of the harnesses to form the shed is controlled by extensions 108, 108' of the outer link member 106, 106 playing in grooves of a camming ring 128 frigid with gear 129.

The weft needles 127, as best shown in FIGS. 18 20, are tubular over the major part of their length and are arcuately curved, with the concavities of their arcs facing the post 102; they are supported at the top of their shafts 125 by generally radial, upwardly slanting arms 126. A weft thread 109 traverses the tubular body of each needle to which it is supplied by a reel not shown. While in this case the swing axes of the needles are vertical rather than inclined, being thus substantially parallel to the direction of the warp in the fabric, they are slanted with reference to their plane of rotation so that their tips are pointed upwardly in the direction of the spreading shed.

The loop inverters 104 have a bifurcate upper end 104 (FIG. 12) by which they engage the weft thread issuing from a needle about to start its insertion stroke. In FIGS. 12, 13, 18 and 19 we have shown a pair of co-operating needles 127, 127a, the latter being mounted on its shaft 125a by an arm designated 126a and carrying a weft thread 109a to be interlinked with a thread 109 which has just penetrated the associated shed with its needle 127. The rise and fall of inverter 104, controlled by the camming groove 116 (FIG. 22) common to all inverters, is so timed that weft thread 109a is drawn into a loop above the tip of needle 127a in the path of the preceding needle 127 emerging from its shed whereby the tip thereof passes through this loop as seen in FIG. 12. Upon the incipient withdrawal stroke of needle 127 and the continuing advance of needle 127a, loop inverter 104 descends so that thread 109a winds itself in a loose knot about the upper leg of the emerging loop of thread 109 as shown for the upper node N of FIG. 15. Thread 109a, drawn into a slipping noose, is engaged in a similar manner by the thread of the next weft needle, not shown, the advance of that needle causing a tensioning of the interlinked loops whereby the loop 109 is untwisted and the loop 109:: is twisted to form a crossover point P as illustrated again for the upper node N in FIG. 16. The corresponding crossover point P of loop 109, eliminated by this untwisting motion, is shown in FIG. 15. The consecutive formation of successive loops and nodes thus produces a simple chain, as illustrated for the lower tier in FIGS. and 16, with loops 109, I090 interlinked by nodes N interconnected with adjoining nodes such as N by cross-links L located inside the tubular fabric. This contrasts with the position of the crosslinks shown in FIG. 14 where, for comparison, the nodes N, N have been represented as they would appear if the loop inverter 104 were not used.

In the embodiment illustrated in FIGS. 11 and 20, the beating of the weft threads against the fell 142 of the tubular fabric 142, which passes through the hollow post 102, is accomplished with the aid of a set of reeds 110 in the form of rigid pins projecting radially from the periphery of a swash plate 110 which is journaled on an angularly offset tip 154 of a shaft 151 coaxial with post 102. The lower end of shaft 151 carries a cover plate 155 to protect the bearing of swash plate 110 against dust and dirt; the swash plate, held against rotation by the warp threads 137, 137 engaging its reeds 110, thus wobbles about a point on the shaft axis so that the reeds are cyclically pressed against the fell 142 in step with the progressive shed formation. It will be understood that, in this case, the movement of the harnesses 144, 144' occurs in a continuous wave, in contrast to the concurrent displacement of a group of such harnesses as in the flat loom described with reference to FIGS. 1 10.

Shaft 151 is journaled in a bearing sleeve 152 and is driven from shaft 111 by a train of bevel gears 146, 147, 149, 150 as well as an intermediate shaft 148.

In FIG. 21 we have shown an alternate arrangement wherein vertically reciprocating reeds 167, 167' are disposed in interleaved relationship, similar to that described above in connection with FIGS. 5 and 6, on respective lay segments 1 159, 159' having lugs I60, 160' slidably mounted on vertical guide rods 158. Camming rollers 161, 161 on members 159, 159' engage in respective grooves 162, 163 in a hub 164 of a gear 165 which is rotatably journaled on a boss 157 depending from a beam 156 rigid with the loom frame. Gear 165 is driven from main shaft 1 11 (FIG. 11) by way of other gears partly illustrated at 166.

The rise and fall of the reeds 167, 167 is controlled by the camming grooves 162, 163 to coincide with the insertion and withdrawal of the juxtaposed weft needles 127 and the opening and closure of the sheds formed by the associated harnesses 144, 144; this has been illustrated for the two diametrically opposite weaving units visible in FIG. 11, the left-hand unit being shown in the beating-down position whereas the right-hand unit is shown with its shed wide open. It may be mentioned that, in contradistinction to the swash-plate drive shown in FIGS. 11 and 20, the cam drive illustrated in FIG. 21 may be designed to provide several simultaneous shed openings and shed closures around the circle, thus increasing the weaving rate per shaft revolution.

Since, in the circular loom of FIGS. 11 22 the Weft needles 27 are peripherally arranged around the tubular fabric so as to enter the curving sheds from the outside, it is important to make the radius of curvature of these needles larger than that of the fabric so that the thread-carrying tip of an inserted needle should not swing too far inwardly and should remain accessible to the tip of the next needle 127a at the intersection of their orbits, i.e. at the boundary between adjoining web sections marked by a warp divider In the weaving of hose of very large diameter the needles could even be straight. Naturally, the aforedescribed thread-clamping means may also be used in such a circular loom to prevent any untimely contraction of a weft loop under stress from a preceding loop in the weft chain.

A fabric structure as produced by the loom of FIGS. 11 22, with progressive stepping of the web sections 20 2f in accordance with the relative staggering of the needle cams, has been illustrated in FIG. 23 in developed form.

We claim:

1. In a loom having a source of warp threads and a supply of weft threads to be interwoven therewith for producing a fabric, the improvement comprising:

a plurality of substantially identical weaving units mutually juxtaposed in a direction generally transverse to said warp threads, the latter forming an array subdivided into a plurality of parallel sections each assigned to one of said weaving units, each weaving unit including shed-forming means engaging the warp threads thereof and individual insertion means for passing a weft thread through a shed formed from the associated warp threads, the insertion means of adjacent weaving units having sweeps intersecting at the boundary of their respective sheds;

drive means for operating said weaving units in staggered relationship with engagement of a weft thread emerging from a preceding shed by a weft thread about to enter a succeeding shed whereby a chain of interlinked weft loops is formed across the array of warp threads; and

reed means synchronized with said drive means for progressively beating said chain against the fell of the resulting fabric.

2. The improvement defined in claim 1 wherein said insertion means comprises a weft needle supported for rotation about an axis generally transverse to the array of warp threads, said weft needle having a thread-carrying tip projecting beyond the associated shed at the end of an insertion stroke and lying outside the shed at the end of a withdrawal stroke.

3. The improvement defined in claim 2 wherein said needle is curved along an are substantially centered on said axis.

4. The improvement defined in claim 2 wherein said needle is tubular and longitudinally traversed by its weft thread.

5. The improvement defined in claim 2 wherein said axis includes a small angle with a line perpendicular to said array of warp threads.

6. The improvement defined in claim 2 wherein said needle is provided with intermittently operable thread-clamping means for arresting its supply of weft threads, said threadclamping means being synchronized with said drive means for operation upon at least partial insertion of the weft thread into the shed to prevent the contraction of a generally triangular loops formed by the weft thread.

7. The improvement defined in claim 6 wherein said threadclamping means is operative during a terminal'phase of said withdrawal stroke for drawing a node between the associated weft thread and the next-following weft thread into its own shed.

8. The improvement defined in claim 2 wherein said reed means comprises a set of battens individually engaging the warp threads of respective sections.

9. The improvement defined in claim 8 wherein said reed means further comprises a second set of battens each paired with a respective batten of the first set, the battens of each pair being provided with interleaved reeds bracketing respective warp threads between them.

10. The improvement defined in claim 9 wherein the battens of each pair are mutually offset, in a direction transversed to the warp threads, by half the width of a section.

11. The improvement defined in claim 9 wherein said interleaved reeds enter between the warp threads from opposite surfaces of the array.

12. The improvement defined in claim 2 wherein said array is tubular, further comprising a supporting tube receiving said array, said weft needles being peripherally mounted on said supporting tube and being arcuately curved about axes parallel to said tube with a radius of curvature greater than that of said tube.

13. The improvement defined in claim 12, further comprising a loop inverter juxtaposed with each weft needle for engaging its thread and displacing it in a loop along the boundary of adjoining sections for engagement by the preceding weft needle upon the emrgence thereof from the associated shed, preparatorily to entry of such weft needle into a generally triangular loop formed by the thread of said preceding weft needle, whereby lengths of weft thread interconnecting adjoining weft chains at the section boundaries are relocated to the inside of the fabric.

14. The improvement defined in claim 12 wherein said reed means comprises a shaft coaxial with said tube, a swash plate mounted on said shaft for wobbling motion, and a set of pins radiating from said swash plate into engagement with said warp threads, said shaft having an angularly offset extension driving said swash plate.

15. The improvement defined in claim 1, further comprising a set of warp dividers traversing said array at the boundaries of adjoining sections. 

1. In a loom having a source of warp threads and a supply of weft threads to be interwoven therewith for producing a fabric, the improvement comprising: a plurality of substantially identical weaving units mutually juxtaposed in a direction generally transverse to said warp threads, the latter forming an array subdivided into a plurality of parallel sections each assigned to one of said weaving units, each weaving unit including shed-forming means engaging the warp threads thereof and individual insertion means for passing a weft thread through a shed formed from the associated warp threads, the insertion means of adjacent weaving units having sweeps intersecting at the boundary of their respective sheds; drive means for operating said weaving units in staggered relationship with engagement of a weft thread emerging from a preceding shed by a weft thread about to enter a succeeding shed whereby a chain of interlinked weft loops is formed across the array of warp threads; and reed means synchronized with said drive means for progressively beating said chain against the fell of the resulting fabric.
 2. The improvement defined in claim 1 wherein said insertion means comprises a weft needle supported for rotation about an axis generally transverse to the array of warp threads, said weft needle having a thread-carrying tip projecting beyond the associated shed at the end of an insertion stroke and lying outside the shed at the end of a withdrawal stroke.
 3. The improvement defined in claim 2 wherein said needle is curved along an arc substantially centered on said axis.
 4. The improvement defined in claim 2 wherein said needle is tubular and longitudinally traversed by its weft thread.
 5. The improvement defined in claim 2 wherein said axis includes a small angle with a line perpendicular to said array of warp threads.
 6. The improvement defined in claim 2 wherein said needle is provided with intermittently operable thread-clamping meaNs for arresting its supply of weft threads, said thread-clamping means being synchronized with said drive means for operation upon at least partial insertion of the weft thread into the shed to prevent the contraction of a generally triangular loops formed by the weft thread.
 7. The improvement defined in claim 6 wherein said thread-clamping means is operative during a terminal phase of said withdrawal stroke for drawing a node between the associated weft thread and the next-following weft thread into its own shed.
 8. The improvement defined in claim 2 wherein said reed means comprises a set of battens individually engaging the warp threads of respective sections.
 9. The improvement defined in claim 8 wherein said reed means further comprises a second set of battens each paired with a respective batten of the first set, the battens of each pair being provided with interleaved reeds bracketing respective warp threads between them.
 10. The improvement defined in claim 9 wherein the battens of each pair are mutually offset, in a direction transversed to the warp threads, by half the width of a section.
 11. The improvement defined in claim 9 wherein said interleaved reeds enter between the warp threads from opposite surfaces of the array.
 12. The improvement defined in claim 2 wherein said array is tubular, further comprising a supporting tube receiving said array, said weft needles being peripherally mounted on said supporting tube and being arcuately curved about axes parallel to said tube with a radius of curvature greater than that of said tube.
 13. The improvement defined in claim 12, further comprising a loop inverter juxtaposed with each weft needle for engaging its thread and displacing it in a loop along the boundary of adjoining sections for engagement by the preceding weft needle upon the emrgence thereof from the associated shed, preparatorily to entry of such weft needle into a generally triangular loop formed by the thread of said preceding weft needle, whereby lengths of weft thread interconnecting adjoining weft chains at the section boundaries are relocated to the inside of the fabric.
 14. The improvement defined in claim 12 wherein said reed means comprises a shaft coaxial with said tube, a swash plate mounted on said shaft for wobbling motion, and a set of pins radiating from said swash plate into engagement with said warp threads, said shaft having an angularly offset extension driving said swash plate.
 15. The improvement defined in claim 1, further comprising a set of warp dividers traversing said array at the boundaries of adjoining sections. 